Hitch lock

ABSTRACT

1. A TRAILER HITCH SOCKET LOCK FOR A TRAILER HITCH INCLUDING A SOCKET FOR RECEIVING A BALL OF A TOWING VEHICLE, SAID LOCK COMPRISING A SUBSTITUTE BALL RECEIVABLE IN SAID SOCKET, DIMENSION-VARYING MEANS ON THE SUBSTITUTE BALL FOR VARYING THE RELATIVE DIMENSIONS OF THE SUBSTITUTE BALL AND THE SOCKET BETWEEN BALL RETAINING AND BALL RELEASING (POSITIONS) RELATIONSHIPS, A MEMBER HAVING MEANS FOR ITS MOVABLE SUPPORT AND HAVING A PORTION ENGAGEABLE WITH SAID DIMENSION-VARYING MEANS TO PRECLUDE OPERATION THEREOF NECESSARY TO ACHIEVE A BALL RELEASING RELATIONSHIP (TOWARD BALL RELEASING POSITION), SAID MEMBER HAVING AN OPERATING PORTION, A HOUSING HAVING A CAVITY INTO WHICH THE SAID OPERATING PORTION OF SAID MEMBER EXTENDS, AND MEANS FOR PREVENTING UNAUTHORIZED ACCESS TO SAID APERATING PORTION INCLUDING (1) A LOCK BODY WHICH MUST BE MOVED FROM AN OPERATIVE POSITION (A LOCK-CONTROLLED BODY REMOVABLY POSITIONED) IN SAID CAVITY TO ENABLE SUCH ACCESS, AND (2) LOCK MEANS FOR SECURING SAID LOCK BODY AGAINST MOVEMENT OUT OF ITS OPERATIVE POSITION. (IN NORMALLY LOCKED CONNECTION THEREWITH AND COMPLETELY CLOSING THE CAVITY AGAINST ACCESS TO THE OPERATING PORTION OF SAID MEMBER WHEN SAID BODY IS IN PLACE IN THE CAVITY, THE SAID OPERATING PORTION OF SAID MEMBER BEING ACCESSIBLE WHEN SAID BODY IS WITHDRAWN FROM SAID CAVITY.)

Oct. 1, 1914 E. A. LONGENECKER HITCH LOCK S Sheets-Sheet 1 OriginalFiled Sept. 20, 1966 IN u 2 N To K E'Ezvsr 9. za/vewscmee Oct. 1, 1974Original Filed Spt. 20, 1966 E. A. LONGENECKER HITCH LOCK 3 Shuts-SheetI m j 0 N \I E HT'O K 4 40 52w: r H. lama/weaken ATTORNEV$ 1974 E. A.LONGENECKER 23,137

HITCH LOCK 3 Sheets-Sheet 3 Original Filed Sept. 20, 1966 INVENT'O 252/57 A? zawazwzcxae W p 'M 1M 7" -r'r'oeusvi United States Patent28,187 HITCH LOCK Ernst A. Longenecker, 71820 Robinwood St., Brookfield,Wis. 53005 Original No. 3,410,580, dated Nov. 12, 1968, Ser. No.

580,444, Sept. 20, 1966. Application for reissue July 20, 1973, Ser. No.381,303

Int. Cl. 360d 1/06 U.S. Cl. 280-507 20 Claims Matter enclosed in heavybrackets [1 appears in the original patent but forms no part of thisreissue specification; matter printed in italics indicates the additionsmade by reissue.

ABSTRACT OF THE DISCLOSURE Generically, it is contemplated that a partmanipulated to release one member from another shall be accessible onlyin a recess in which a lock body is housed and in which it can belocked. In other words, the entire lock body is rendered substantiallyinaccessible by housing it in the said recess where only the key slot isexposed. In most embodiments, the lock body is removed in its entiretyto give access to the member that secures the parts in connection.However, in one embodiment, the lock body is not completely withdrawnfrom the recess, but is only partially withdrawn, and the movement ofthe lock body itself to and from its fully housed position manipulatesthe mechanism.

Another generic concept involves an arrangement whereby a screw of somesort releasably secures the detachable parts in connection and isaccessible for manipulation only by removal of the lock body from therecess.

Several species of the invention relate to makes of preventing theft ofan unconnected trailer. Broadly, it is an objective of this invention topreclude the entrance of a towing vehicle bail into the hitch socketeither by filling the socket with a lock ball or by covering the end ofthe hitch fitting and the entrance to the socket with an appropriatecover locked thereto.

In embodiments of the first type, a substitute locking ball receivableinto the socket of a conventional trailer hitch as a substitute for theball of the authorized towing vehicle has screw-controlled means forvarying relative dimensions of the socket and the substitute ballwhereby to prevent or permit egress of the ball. When the ball is inplace, it prevents exposure of the socket to receipt of the ball of anunauthorized towing vehicle. A substitute ball and means for forcing andlocking it into the fixedwalled recess of a conventional trailer hitchsocket is a generic concept believed to be new as such, regardless ofthe specific locking means employed.

Since the socketed fitting of a conventional trailer hitch is usuallyexternally convex, having the general shape of a ball, the cover whichcloses its ball-receiving opening may be socketed to receive the fittingto close its ball-receiving opening. The cover has a shoulder whichenters the opening sufiiciently so that it can be released only bybodily displacement, such displacement being prevented by a screw whichis so disposed that it can be rendered in accessible in a recessenclosed by a lock body having little or nothing exposed except the keyslot.

A rugged means adjustable to and from a position for holding the partsdisplaced and rendered inaccessible by a lock body as above described isbelieved to be generically new. In each of the several trailer hitchembodiments herein disclosed, a set screw displaces the interengagedparts to render them inseparable until the set screw is released, theset screw being rendered inaccessible by a lock body which is socketedin the device and has no parts exposed which could be damaged or brokento Re. 28,187 Reiissued Oct. 1, 1974 gain access to the socket withoutalso destroying the socket itself and hence thwarting the planned theft.

One embodiment somewhat different from the others involves a clampingscrew which may be used upon any desired apparatus, an outboard motorbeing an example. Instead of preventing the screw from rotating, theinstant embodiment permits the screw to be rotated freely and the lockpermits or requires the nut to rotate with it so that no clamping occursunless the nut is restrained against rotation. This can be done onlythrough control mechanism which is normally inaccessible behind a lockbody normally fixed at the bottom of a recess, where it displaces thecontrol parts to positions in which they release the nut to permit itfreedom of rotation so that the clamp screw cannot be unclamped.

Background of the invention Padlocks and the like as heretofore usedhave been particularly vulnerable because their hasps are exposed wherethey can be cut. In most embodiments of the present invention, the lockdoes not of itself secured the parts together but it is movably mountedin a recess where it obscures and renders inaccessible the member thatactually does the locking.

The invention is by no means limited to the locking of a trailer hitchbut it has particular advantage in that field. Many devices have beenproposed for preventing theft of trailers but all of them heretoforehave been of such a nature that the breakage or deflection of exposedparts would open the socket to permit the insertion of a ball of anunauthorized towing vehicle. It is a common occurrence for an owner of atrailer to have the trailer stolen when he is away with his car. Suchtheft is precluded by the substitute ball which is locked into thetrailer socket according to the present invention.

Description of the invention FIG. 1 is a view in side elevation showinga device embodying the invention.

FIG. 2 is a plan view of the device shown in FIG. 1.

FIG. 3 is an enlarged detail view of a conventional lock showing how thelock is converted for use in the device of FIG. 1.

FIG. 4 is a plan view of the lock post severed from the lock in FIG. 3for use in accordance with the present invention.

FIG. 5 is a view in longitudinal vertical section showing the device ofthe persent invention in use in a wellknown type of trailer hitchsocket, the lock being seprately shown in side elevation.

FIG. 5A is a fragmentary view similar to FIG. 5 showing the partsinterlocked in ditierent relative positions.

FIG. 6 is a view like FIG. 5 showing another conventional socket withthe device of the present invention in use therein, the lock being inplace in the recess provded for it.

FIG. 7 is a view in section on the line 77 of FIG. 1, with the lockpartially inserted in the recess provided for it.

FIG. 8 shows in longitudinal section the device of the present inventionused to lock a hitch ball rather than a hitch socket by providing acover which can be secured about the ball portion of the hitch, the lockbeing illustrated in its separated position.

FIG. 9 is a plan view of an entirely different style of trailer hitch,the tongue being fragmcntarily illustrated.

FIG. 10 is a view taken in longitudinal section on the line 1010 of FIG.9, the lock being separately illustrated.

FIG. 11 shows a modified embodiment of the invention partially in sideelevation and partially broken away to the plane indicated at 11-11 inFIG. 12.

FIG. 12 is a view taken in section on the line 12-12 of FIG. 11.

FIG. 13 is a fragmentary view on the line 1313 of FIG. 12.

The ball is of conventional dimensions to be received into the trailerhitch sockets shown at .12 in FIG. 5 and at 14 in FIG. 6. The device ofFIG. 5 has a relatively fixed jaw 16 and a movable jaw 18 which has alink 20 connecting it with a hand lever 22 on the trailer tongue 24. Thejaw 18 is raised and lowered by lever 22 between ball unlocking andlocking position. FIG. 5 shows the jaw 18 in locking engagement with thesubstitute ball 10 provided in accordance with the present invention.

The ball 10 has a slot 28 which is spanned near its lower end by apintle 30 upon which the dog member 32 is pivotally movable between thefull and dotted line positions in which it is illustrated in FIGS. 1 and5. In FIG. 5, dog 32 is shown in full lines in a retracted posi tion.The dog 32 is not used when the hitch 55 is locked with the jaw in itslocked position. However, FIG. 5A shows how the same parts are usable tolock the hitch when the jaw 18 is in its retracted or open position. Asshown in FIG. 5A, the dog 32 has been swung upwardly so that itsshoulder 33 is engaged with the surface 13 of the socketed female hitchcasting 15. The thrust of set screw 34 is now exerted on the margin 35of dog 32 to force the dog against surface 13 of the casting 15, wherebyto make it impossible to withdraw the ball 10 from the socket 12. Inthis position, no direct contact between the dog 32 and the movable jam18 is required. To emphasize this point, clearance is illustratedbetween these parts (although no clearance is necessary).

In the device shown in FIG. 6, movable jaw 180 is reciprocablehorizontally toward and from the fixed jaw 160 by means not shown. Thedevice is conventional and the movement of the jaw 180 forth and back isin the direction indicated by the arrow 26. FIG. 6 shows the hitch jaw180 in its open or retracted position.

Essentially the same substitute locking ball 10 is used in both theconventional type of hitches shown in FIG. 5 and that shown in FIG. 6.It has an integral base 54 which so closes the socket below the ball asto make the socket inaccessible, thereby precluding introduction of aprying implement.

Threaded within the ball 10 at an oblique angle is a set screw 34 which,in the instant device, is designed to be operated by an Allen wrench 36.The threaded bore 38 in which the set screw operates opens at its lowerend into a recess 40 in a base 54 which is preferably integral with theball. This recess receives a generally conventional lock body 42. Asbest shown in FIG. 3, the lock body was originally provided with a hasp44. Both legs of the hasp have been sawed off on the broken line 46. Oneleg is biased outwardly by spring 47 and may be left in the lock as astud 48. The lock body and the notched bar 50 constituting the other legare separable when the lock dog 51 is retracted by operation of key 52.

The ball 10 is provided with the aforesaid integral base 54. The notchedbar 50 is attached to the base at the rear end of the recess 40 and isso positioned that when the lock body 42 is inserted into recess 40 thenotched bar 50 projects into the lock body to be engaged by its keeper51 in routine fashion. When the lock body is in place in the recess andthe key 52 is withdrawn, no part of the lock body is exposed with theexception of the end having the key slot. The recess preferably openshorizontally so that the key slot is readily accessible. A bore may beprovided in the base 54 for the stud 48 if this is non-yieldable in thelock body. Normally stud 48 yields by compression of spring 47.

In the case of the type of hitch shown in FIG. 5, the screw 340 projectsacross part of the upper end portion 58 of the movable jaw 18, thussecuring the jaw against retraction to its open position. The ball 10 isthereby securely held within the trailer hitch socket 12 to precludeentry of an unauthorized towing vehicle ball into that socket. Yet thedevice may be opened with ease by the holder of the proper key 52. Bymanipulating the lock 42 with the key and withdrawing the lock from therecess 40 and by retracting the screw 340 with wrench 36, the movablejaw becomes released and can be lifted by lever 22 to permit completewithdrawal of the locking ball 10.

Similarly, when the movable jaw 18 is retracted from the position ofFIG. 5 to the position of FIG. 5A, the same set screw 340, now operatingon dog 32, will hold the ball 10 within socket 12 by forcing it againstthe immovable side wall portion of the socket. In effect, the ball hasbeen expanded by the action of the set screw upon the dog 32.

In the type of hitch shown in FIG. 6, in which the movable jaw operateshorizontally rather than vertically, this jaw is left in its retractedposition and the dog 32 carried by the base 54 is swung upwardly aboutpintle 30 to a position such that it may be engaged by set screw 34 andforced outwardly into engagement with the retracted jaw 180. Both in thedevice of FIG. 5 and that of FIG. 6, the change in relative dimensionsof the ball and socket will preclude withdrawal of the locking ballexcept by authorized manipulation of the lock. Use of the key 52 is aprerequisite.

In both devices the retraction of the locking device leaves the socketunimpaired and unchanged so that it can be used conventionally inaccordance with its intended function. It is to be noted that a screw isused as a locking device in both types of sockets. It is, of course, tobe noted that the device need not be designed to be universal. A lockingdevice embodying the invention made solely for the type of trailer hitchshown in FIG. 5 does not require the use of dog member 32. Similarly, ifthe device is used solely in the type of hitch shown in FIG. 6, the dog32 could have a much reduced range of movement, since it would not haveto swing outwardly to the position in which it is shown in FIG. 5.However, the locking device as illustrated is of universal applicationto the two types of jaws and hitches shown. These, at the present time,represent the majority of all hitches in common use.

In the embodiment of the invention shown in FIG. 8, theft of the traileris prevented by simply placing a cover member 62 on the trailer hitchfitting at the front end of the trailer tongue 59 and locking the covermember against removal. With the cover member thus locked in place. itsbase portion 64 closes the downwardly opening mouth of the socket 60 inthe trailer hitch fitting, making it impossible to hitch the trailer toa towing vehicle.

The cover momber 62 is locked in place through the coat-tion of a lug 66and a set screw 68. The lug enters the mouth of the socket and engagesthe inwardly facing margin 70 which defines the foremost edge or lip ofthe mouth of the socket, and is held against disengagement therefrom bythe set screw 68 when the latter is screwed in to engage the top of thesocket. With the screw thus positioned, downward movement of the covermember with respect to the trailer hitch firtingas would be needed todisengage the lug 66 from: the marginal edge 70is impossible.

[In the device of FIG. 8, the trailer tongue 59 is provided with a hitchhaving the usual spherically socketed terminal portion 60. In order tosecure this particular construction against theft, I provide a cover 62in which terminal 60 is receivable to be enclosed and locked to prevententry into the hitch socket of the ball of an unauthorized towingvehicle. The cover 62 has a base portion 64 extending beneath the hollowlower portion of the socket 60. An integral lug 66 engages within thehollow portion 60 so that the parts can be separated only by relativevertical movement. The set screw 68 engages over the trailer tongue tohold the lower margin 70 behind the shoulder provided by lug 66 so thatthe cover is securely locked to the end of the tongue to prevent anyconventional coupling operation until the cover is removed] Aspreviously, the outer end 72 of the set screw which is socketed toreceive a wrench is completely inaccessible when the lock body 74 is inthe recess 76. With the lock body removed as shown in FIG. 6, the end ofthe set screw is accessible and it may be retracted to permit removal ofthe cover member.

FIGS. 9 and show the application of principles of the invention toanother very ditferent type of hitch. The tongue or tow bar 78 ends in aring or eye 80 which, in use, is dropped over a peg on a towing vehicle.The ring 80 is convexly rounded in each cross section for a certainuniversality of movement. This type of hitch is commonly used intrailers carrying air compressors, welders, and the like.

So that the eye within ring 80 will not receive the peg of a towingvehicle, I engage a dislike plug 82 in each H opposite side of ring 80.Each of these plugs has a shoulder recess 84 into which I place theinserts 86 and 88 and connect these by the shoulder bolt 90. The bolt isthreaded into the insert 88 and seats against the shoulder 92 of insert86. The housing 98 on insert 86 provides recess 100 for the lock body102, as in prior constructions. The spring-pressed prong 104 remainsyieldably attached to the lock body while the notched prong 106 is fixedin the housing 98 at the rear of the recess so that the lock body can bedetachably secured to it and is releasable only by the key 108.

When the lock body is removed, the head of shoulder bolt 90 becomesaccessible through the opening 110 and recess 100. When the bolt 90 isunscrewed, the disks 82 drop from the eye of the ring 80 at the end oftongue 78, leaving the ring accessible to the peg of a towing vehicle.FGS. 9 and 10 show the mechanism locked in place but as viewed, the bolt90 is still exposed to the port 110. It will be concealed andinaccessible when the lock body is inserted in recess 100 and securedtherein.

The construction shown in FIGS. 11, 12, and 13 shown means for using thepresent invention to secure a clamp screw 120 against unauthorizedrelease. As an example of something which may be held by such a clampscrew, I have fragmentarily illustrated an outboard motor bracket 122engaged over a boat transom 124 against which the swiveled head 126 ofthe clamp screw 120 is engaged.

The bracket as shown is designed to receive two of the clamp screws 120.

Rotatable within the bracket at two laterally spaced points are sleevenuts 130 both provided at peripherally spaced points 'with axiallyextending ribs 132. The nuts are mounted to turn freely in the bracketand may even be provided with appropriate anti-friction bearings 133 tofacilitate their rotation. Obviously, no clamping or releasing movementof either of the screws 120 will be possible if the nuts are free torotate.

Within the bracket are levers 134 fulcrumed at 136 and biased by acommon connecting spring 138. At their free ends, these levels have dogs140 engageable under spring bias with the external ribs on the locksleeves 130. When the dogs are so engaged, the sleeves will be heldagainst rotation. Under this condition, the clamp bolts 120 can bethreaded inwardly or outwardly through the respective sleeves.

The bracket provides the usual recess 144 for the lock body 146,exposing only the keyhole for the key 148. In this instance, as bestshown in FIG. 13, a set screw engages the spring-pressed prong 104 ofthe lock body so that the lock body can only move part way out of therecess 144 to the limit of movement of the lock body with respect toprong 104. When the lock body is moved partly out, the spring 138engages the dog 140 with the sleeve nuts 130 so that the clamp screwsfunction. When the lock body is pushed inwardly, it displaces the pads150 of levers 134 to disengage the lugs from the sleeve nuts so that theclamp screws are locked against functioning.

To prevent the screws from turning in the nuts when the lock is inplace, plastic plugs 151 are located in radial holes in the nuts 130 andbear against the threads of the screws 120. However, when the nuts 130are fixed against rotation by engagement of the dogs in the ribs 132,the friction of the plugs 151 is overcome and the screws may be advancedor retracted to clamp or remove the bracket 122 from the transom 124.

Many other embodiments of the invention are possible and have beentested. The embodiment illustrated has many advantages over all otherswhich are known to I claim:

1. A trailer hitch socket lock for a trailer bitch including a socketfor receiving a ball of a towing vehicle, said lock comprising asubstitute ball receivable in said socket, dimension-varying means onthe substitute ball for varying the relative dimensions of thesubstitute ball and the socket between ball retaining and ball releasing[positions] relationships, a member having means for its movable supportand having a portion engageable with said dimension-varying means topreclude operation thereof necessary to achieve a ball releasingrelationship [toward ball releasing position], said member having anoperating portion, a housing having a cavity into which the saidoperating portion of said member extends, and means for preventingunauthorized access to said operating portion including (1 a lock bodywhich must be moved from an operative position :[a lock-controlled bodyremovably positioned] in said cavity to enable such access, and

(2) lock means for securing said lock body against movement out of itsoperative position. [in normally locked connection therewith andcompletely closing the cavity against access to the operating portion ofsaid member when said body is in place in the cavity, the said operatingportion of said member being accessible when said body is withdrawn fromsaid cavity] 2. A trailer hitch socket lock according to claim 1 inwhich the said member is a screw, the substitute ball having a baseconstituting said housing and provided with a recess constituting saidcavity and in which the said operating portion of the screw is normallyaccessible. said recess receiving said lock [-controlled] body[including a lock casing detachably fitted to the recess for closingsaid recess about] when the latter is in its operative position tothereby prevent access to the operating portion of the screw.

3. A trailer hitch lock according to claim 2 in which the lock [casing]body has a hole and the said base has a notched bar fixed to it andprojecting into the recess to register with, and be received into, saidlock [casing] body when the lock [casing] body is in its operativeposition in the recess.

4. A trailer hitch socket lock according to claim 1 in which the [first]said dimension-varying means comprises a movable jaw for which thesocket provides a complementary fixed jaw.

5. A trailer hitch socket lock according to claim 1 in which said[first] dimension-varying means comprises a member connected for pivotalmovement with respect to the substitute ball for engagement with a jawwith which the socket is provided, said member in its operative positionincreasing the effective diameter of the ball to preclude removalthereof from the socket.

6. A trailer hitch socket lock according to claim 1 in which thesubstitute ball has a base connected therewith to be disposed beneaththe trailer hitch socket when the substitute ball is in place therein,said substitute ball and base having a slot, the dimension-varying means[for varying relative dimensions] comprising a dog member disposed in[the] said slot and having pivotal connection with the base for movementinto and out of the slot.

7. A trailer hitch socket lock according to claim 6 in which [the] saidfirst said member comprises a set screw in threaded connection with thesubstitute ball and for which said dog member provides a seat, said basehaving a recess constituting said cavity and in which the end of the setscrew is normally accessible for adjustment of the set screw, and [alock having a body] wherein said lock body has a portion receivable into[the] said recess, and [having] wherein said lock means iskey-controlled and secures the lock body [means for securing it] to thebase within the recess [for precluding] to preclude access to the setscrew.

8. A trailer hitch socket lock according to claim 1 in which the trailerhitch socket comprises a movable jaw and a fixed jaw and means foractuating the movable jaw to and from ball retaining position, the saidmember being a set screw adjustable to and from a position for fixingthe movable jaw in its ball-retaining position, the said movable jawconstituting the said dimension varying means.

9. A trailer hitch socket lock according to claim 8 in which said setscrew project through the substitute ball and engages the movable jaw tohold the latter in ballretaining position.

10. A trailer hitch socket lock according to claim 9 in which a baseattached to the substitute ball is normally disposed beneath the socketand provided with a recess which constitutes said cavity and in which[an] the operating portion of the set screw is normally accessible, andwherein the [a] lock body has a [having] key-releasable detachableconnection with said base, and wherein said lock body [being] when inits operative position is disposed in the recess in a position renderingthe set screw inaccessible [when the body is connected with the base].

11. In a lock organization, the combination with relatively movablefirst and second parts, said first part having means mounting it formovement between advanced and retracted positions and said second partsubstantially enclosing said first part and having a cavity in whichsaid first part is accessible upon removal of the lock body hereinaftermentioned, a lock body removably positioned in the cavity and having acontrolled lock mechanism [and] with an exposed actuator, means on thesecond part with which the lock mechanism is releasably connected andfrom which it may be released by manipulation of the actuator, the saidbody substantially filling the cross section of the cavity whereby thepresence of the lock body in the cavity of the second part renders thefirst part inaccessible.

12. A lock organization according to claim 11 in which the said firstpart comprises a screwthreaded member.

13. A lock organization according to claim 12 in which the saidscrewthreaded member is rotatable in the second part.

14. A lock organization according to claim 11 in which the first partcomprises a portion exposed to manipulation through said [recess] cavitywhen the lock body is absent therefrom, said organization furtherincluding a member having means detachably interlocking it with saidsecond part and releasable solely by manipulation of the first part.

[15. In a lock organization, the combination of a recessed first member,a lock body removably disposed in the recess of the first member andhaving key-controlled mechanism detachably fixing it in the recess andprovided with a key slot to receive a key for the manipulation of saidmechanism, said lock organization including a part accessible in therecess only on removal of said lock body and operable only therethrough,said lock body substantially closing said recess when fixed therein,whereby to preclude access to said part until said body is released bysaid mechanism and removed from said recess] [16. In lock organizationaccording to claim 15, a threaded sleeve rotatable in said member, aclamp screw threaded in the sleeve and threadedly movable through thesleeve only when the sleeve is fixed again rotation respecting themember, said part having means normally engaged with said sleeve forsecuring the sleeve against rotation and being subject to manipulationthrough the recess for disengagement of the part from the sleeve toaccommodate sleeve rotation respecting said member and thereby topreclude threaded movement of the set screw in the sleeve] 17. A trailerhitch lock comprising the combination with a socketed trailer hitchfitting, of a complementary member adapted to render the socket of saidfitting inaccessible to the ball of a towing vehicle, said memberincluding means engageable with and readily removable from said fittingin one relative position and interlocked therewith in another relativeposition, manually adjustable means movable between a releasing positionand a position for holding said member and said fitting in theinterlocked relative position, and a lock body detachably connected withsaid member in a position in which it renders said manually adjustablemeans inaccessible for manual adjustment when the lock body is connectedwith said member, said lock body having lock means releasably connectingit with said member.

18. A trailer hitch lock according to claim 17 in which said member hasa recess in which said lock body is removably disposed, the saidmanually adjustable means having in said recess the only portion bywhich it is manually adjustable and said portion being beyond said bodyin the recess and rendered inaccessible when the body is disposed in therecess.

19. A trailer hitch lock according to claim 18 in which said memberconstitutes a cover into which the socketed trailer hitch fitting isreceivable, said cover having a portion extending beneath the socket ofsaid fitting to preelude entry of a ball therein, said portion having ashouldered boss disposed in the socket of said fitting andinterlockingly engaged therewith, the fitting being disengageable fromthe boss by relative upward movement only when said manually adjustablemeans is in said releasing position, the manually adjustable meanscomprising a screw movable to and from engagement with said fitting andacting thereon to hold the fitting interlockingly engaged with the boss,retraction of the screw permitting disengagement when the lock body isremoved from the recess to make the screw accessible.

20. In a lock organization, the combination of:

A. a recessed member;

B. an internally threaded sleeve freely rotatably mounted in saidrecessed member;

C. a clamp screw threaded in the sleeve and threadedly movable throughthe sleeve only when the sleeve is restrained against turning in saidrecessed member;

D. a movable restraining member in the recessed member,

said restraining member being movable to and from an operative positionrestraining the sleeve against turning;

E. a lock body movably disposed in said recessed member for movement toand from an operative position in which it holds said restraining memberin an inoperative position; and

F. locking mechanism in said body for releasably securing the same inits operative position.

21. A trailer hitch lock comprising the combination with a socketedtrailer hitch, the socket of which has an inwardly facing margindefining part of the mouth of the socket, of:

A. a cover unit movable to and from an operative position engaged withthe trailer hitch fitting, in which position it prevents entry into thesocket of the ball of a towing vehicle; retaining means forming part ofthe cover unit and engageable with said inwardly facing margin toprevent movement of the cover unit from its operative position;

B. a screw also forming part of the cover unit and operable when screwedin to maintain said retaining means engaged with said inwardly facingmargin;

C. tool engageable means on said screw to enable the screw to be screwedin and out; and

1). means for preventing nntauthorized access to said tool engageablemeans including (1) a lock body which must be moved from an operativeposition to enable such access; and (2) key controlled means forpreventing movement of said lock body out of its operative position.

22. A trailer lock to guard against unauthorized towing of the trailerby preventing entry of the ball of a towing vehicle into the socket ofthe hitch fitting of the trailer, comprising:

A. a cover unit placeable on the trailer hitch fitting and when inposition thereon closing the mouth of the socket of the fitting;

B. a screw threaded into the cover unit and so located that its innerend portion bears against an adjacent surface of the trailer hitchfitting to hold the cover unit against removal therefrom when the screwis turned in;

C. tool engageable means on the outer end of the screw to enable thescrew to be turned in and out by an appropriate tool when the toolengageable means is accessible;

D. the cover unit having a cavity opening to the exterior thereof andthrough which said tool engageable means is accessible;

5 E. means for preventing access through said cavity to said toolengageable means, including a lock body which must be moved from anoperative position in said cavity to enable such access; and

F. key controlled means for preventing movement of said lock body out ofits operative position.

References Cited The following references, cited by the Examiner, are ofrecord in the patented file of this patent or the original patent.

UNITED STATES PATENTS 3,139,291 6/1964 Geresy 280507 3,213,653 10/1965Probacso 70166 3,226,133 12/1965 Geresy 280507 3,276,835 10/1966 Hall70-169 2,854,256 9/1958 Lamberson 2805l2 OTHER REFERENCES Publication ofChicago Lock C0., 1964.

ROBERT R. SONG, Primary Examiner US. Cl. X.R. 166

